Bug#944777: initramfs-tools-core: Resume fails when UUID= syntax used in conf.d/resume.

[Glenn Washburn <development@efficientek.com>]

Package: initramfs-tools-core
Version: 0.130ubuntu3.9
Severity: normal
Tags: newcomer

Dear Maintainer,

Resume from hibernation will fail when /etc/initramfs-tools/conf.d/resume
contains "RESUME=UUID=<UUID of hibernation image>".  According to NEWS this
should work.  The reason is does not is because UUID= processing is only done
for the resume kernel parameter (see init lines 123-128). No processing is done
for the RESUME shell variable included from conf.d. Recognizing that
conf.d/resume is being sourced as a script in init, I've created a hack to fix
by adding the processing in the resume file. My resume file looks like this:

"""
RESUME=UUID=deadbeef-cafe-dead-beef-cafedeadbeef

case $RESUME in
    UUID=*)
        RESUME="/dev/disk/by-uuid/${RESUME#UUID=}"
esac
"""

Incidentally, I believe this is the issue in #872664. I chose to create a new
bug because that one is unnecessarily specific.  The bug applies to all versions
on all platforms.

I suggest that the case be moved out of the resume= kernel param handling and
added just after line 206, before the "resume" variable is set. Actually, I see
no reason to use the RESUME variable aside from the fact that its what you're
supposed to use in the conf.d/resume file.  But its confusing and inconsistent
to provide "resume=UUID=" as the kernel parameter and "RESUME=UUID=" in the
conf.d/resume file.

Attached is a patch exemplifying my proposed changes (not tested). The patch
should allow for documentation to notify about the depreciation of RESUME= in
conf.d/resume and to start using resume= instead, but to continue being
backwards compatible with the old syntax. The hooks scripts would need to be
updated to account for the new variable (pretty trivial change, something like
"RESUME=${RESUME:-$resume}").

Glenn

diff --git a/init b/init
index 1cc96c3..11788fb 100755
--- a/init
+++ b/init
@@ -121,11 +121,7 @@ for x in $(cat /proc/cmdline); do
 		UBIMTD=${x#ubi.mtd=}
 		;;
 	resume=*)
-		RESUME="${x#resume=}"
-		case $RESUME in
-		UUID=*)
-			RESUME="/dev/disk/by-uuid/${RESUME#UUID=}"
-		esac
+		resume="${x#resume=}"
 		;;
 	resume_offset=*)
 		resume_offset="${x#resume_offset=}"
@@ -201,10 +197,15 @@ if [ -z "${BOOT}" ]; then
 	BOOT=local
 fi
 
-if [ -n "${noresume}" ] || [ "$RESUME" = none ]; then
+if [ -n "${noresume}" ] || [ "${resume:-$RESUME}" = none ]; then
 	noresume=y
+	unset resume
 else
-	resume=${RESUME:-}
+	resume=${resume:-$RESUME}
+	case $resume in
+	UUID=*)
+		resume="/dev/disk/by-uuid/${resume#UUID=}"
+	esac
 fi
 
 mount -t tmpfs -o "nodev,noexec,nosuid,size=${RUNSIZE:-10%},mode=0755" tmpfs /run